The potential of 4D printing in the development of coated expandable drug delivery systems targeting longlasting retention and controlled release of drugs into hollow muscular organ has recently been investigated. In this respect, the shape memory behavior of a pharmaceutical-grade poly(vinyl alcohol) (PVA) turned out effective for attaining prototypes capable to be programmed in a temporary configuration suitable for administration, and to recover the original encumbered shape ensuring retention at the target site. Moreover, the shape memory effect was shown independent of the presence of insoluble but permeable coatings. Based on the encouraging results collected so far at the lab-scale using a home-made equipment, in this work the industrial scale-up of the coating process was approached in collaboration with a company leader in the manufacturing of pharmaceutical machinery. Dealing with reservoir-like expandable prototypes suitable for intravesical applications, a dedicated coating process was set-up using an Eudragit® NE-based formulation. Samples provided with different original and temporary shapes, printed structures and fillings of the inner cavities were considered as substrates. The robustness of the process was demonstrated checking the coated prototypes in terms of physical technological properties, shape memory effect and release performance in urine simulated fluids.

This trial contributes to the development of a novel coating process of very fine powders with diameters of around 30μm. The innovation lies in Freund-Vector’s patented wurster spray system that utilizes an outer sleeve placed around the wurster gun called the Wurster Accelerator. The accelerator creates an adjustable air curtain that diverts product away from the spray nozzle tip, optimizing product movement through the spray zone and reduces processing times.

A process analytical technology (PAT) method relying on near infrared (NIR) diffuse reflectance spectrometry was developed to determine the average coating thickness applied and the weight gained by tablets during coating process. The NIR device was installed inside the pan directly in contact with the cores under processing and relevant spectra were recorded in real time during the entire coat-ing process. The method required principal component analysis (PCA) and partial least squares regression (PLS). The primary methods to calibrate PLS are tablet weight gain and coating thickness, they were carried out using the chemometric methods. The PLS-model was employed as the calibration curve for an online process monitoring and was based on the spectra obtained from the tablets during coating, pretreated with SNV and first derivative, and ordered into one object. This way, the method developed could be advantageously used for in-line PAT monitoring. Additional characterization insights were attained by calibrating the spectra versus the weight gain data obtained from at-line tablet weighing. Overall, the possibility to monitor multiple parameters using just one device and one spectrum was demonstrated.

Wurster coating of multi-particulates with polymer suspensions and solutions is widespread in the pharmaceutical industry. Several formulations for polymer coatings of aqueous dispersions and organic solvent based polymers require glidants such as talc to be suspended into the solutions to cut down on tackiness.

This trial contributes to the development of a novel coating process for fine particles with diameters of around 40μm. The innovation lies in the use of Freund-Vector’s patented Wurster spray system that utilizes an outer sleeve placed around the Wurster gun called the Wurster Accelerator. The accelerator creates an air curtain that diverts product away from the spray nozzle tip, optimizing product movement through the spray zone and reduces processing times. The system is suited for the coating of particles ranging from fine powders (~10 micron) up to small pellets (2-3 mm).